(Adds portfolio manager quotes and details on geopolitics, gold and telecom stocks and updates prices)
* TSX ends up 17.65 points, or 0.12 percent, at 15,269.85
* Seven of the TSX's 10 main groups climb
By Fergal Smith
TORONTO, Dec 19 (Reuters) - Canada's main stock index gained for the third straight session on Monday, with gold miners and telecom shares climbing as political tensions rose and bond yields declined.
The most influential movers on the index included Agnico Eagle Mines Ltd, which rose nearly 3 percent to C$51.18, and Barrick Gold Corp, which advanced 0.8 percent to C$19.10.
Gold edged higher as expectations of tighter U.S. monetary policy and a stronger U.S. dollar were offset by geopolitical tensions after the Russian ambassador to Turkey was shot dead at an Ankara art gallery.
Telecom stocks rose 0.6 percent, with Rogers Communications Inc climbing 1.6 percent to C$51.73, as safe haven demand helped drive bond yields lower.
Defensive sectors, such as telecoms, have benefited from a low yield environment. They had underperformed recently as bond yields climb.
The Toronto Stock Exchange's S&P/TSX composite index , which has gained 17 percent this year, closed up 17.65 points, or 0.12 percent, at 15,269.85.
Investor expectations of U.S. economic stimulus have helped the TSX and Wall Street rally since the U.S. election in November.
"We have had such a good rise in both markets that I think maybe some of the value is going out of some of these stocks," said John Kinsey, portfolio manager at Caldwell Securities.
"The wild card in all of this is (U.S. President-elect Donald Trump) and we don't know what he is going to do."
Investors also worry that policy will take time to be implemented and will likely change as it makes its way through Congress.
BlackBerry Ltd plans to invest C$100 million in a new autonomous vehicle-testing hub over several years, the company's chief executive said, marking a change of direction for the smartphone pioneer.
The company's shares rose 2.3 percent to C$10.34.
Brazil will challenge government funding for Bombardier Inc at the World Trade Organization.
Still, Bombardier's shares surged for the second straight day, up 6.8 percent at C$2.19.
The overall industrials group rose 0.4 percent, while financials gained 0.1 percent despite a 1.5 percent drop in the shares of Fairfax Financial Holdings Ltd to C$605.00
The insurance group has agreed to buy Swiss insurer Allied World Assurance Company Holdings AG for $4.9 billion in cash and stock.
The materials group, which includes precious and base metals miners and fertilizer companies, dipped 0.1 percent, while energy was little changed.
U.S. crude prices settled up 22 cents at $52.12 a barrel. (Reporting by Fergal Smith; Editing by James Dalgleish and Alistair Bell)